Thread: Drilling of circular saw blades-advice please

No, it would not but I think you are wasting your money. Sell them on and use the proceeds to buy new blades. The machining would be more than it is worth.

John

Do you know anyone with a Metalwork Lathe? If not you could appeal to the MetalWork Forum for someone close by who could do them for you for a box of beers

There would not be an easy way to hold them on a lathe. Milling machine possibly, but given the cost and dangers of an out of balance blade, I would sell them and buy new.

What about a new 16mm arbor washer to suit? Should be available off the shelf (via the interweb) from the USA.

5/8" & 1" are their two common sized arbours, and provide imperial alternatives to the metric washers used on Euro & Oz models.

In my technical naivety, had thought perhaps centrally clamped to timber on a drill press table, 30mm drill bit, cooling cutting fluid, it may work ok.
Thanks to all for advice.
David, if the 30mm hole was a few microns out, would this create danger considering the blade centre is clamped between mounting flanges of perhaps 70mm diameter?

Originally Posted by Ratbag

What about a new 16mm arbor washer to suit? Should be available off the shelf (via the interweb) from the USA.

5/8" & 1" are their two common sized arbours, and provide imperial alternatives to the metric washers used on Euro & Oz models.

Thanks Ratbag, the problem is the other way. I need to go up from 15.9mm to 30mm, not the other way. Cheers mate, Redbog

What I meant was an arbor FLANGE, not a washer. i.e. the metallic disc that fits betwixt arbor and blade, flanged to hold the latter concentrically.

Originally Posted by Redbog

if the 30mm hole was a few microns out, would this create danger considering the blade centre is clamped between mounting flanges of perhaps 70mm diameter?

No.
I once bought a new drop saw (contractor quality), and from new it vibrated in use which was annoying but not a biggy. When I had the blade touched up for the first time the saw doctor asked who had done it last time, because it was not concentric.

Originally Posted by Ratbag

What I meant was an arbor FLANGE, not a washer. i.e. the metallic disc that fits betwixt arbor and blade, flanged to hold the latter concentrically.

That'd work.

Yes, I'm aware of your needs.

That's why I corrected my original post. An arbor washer sizes a blade's arbor downwards, however an arbor flange is the disc fitted to & made by the saw's manufacturer to hold the blade concentrically. It is thicker in the arbor than the blade's plate, but true to the arbor's diameter with the flanged section correctly seating the blade's arbor hole concentrically. It acts in concert with the pressure washer and nut to hold the blade firmly in place.

If you order from the USA the correctly sized (i.e. 5/8") imperial equivalent flanged washer for the make and model of saw you have then your imperial blades will be compatible without any modification.

Originally Posted by Ratbag

Yes, I'm aware of your needs.

That's why I corrected my original post. An arbor washer sizes a blade's arbor downwards, however an arbor flange is the disc fitted to & made by the saw's manufacturer to hold the blade concentrically. It is thicker in the arbor than the blade's plate, but true to the arbor's diameter with the flanged section correctly seating the blade's arbor hole concentrically. It acts in concert with the pressure washer and nut to hold the blade firmly in place.

If you order from the USA the correctly sized (i.e. 5/8") imperial equivalent flanged washer for the make and model of saw you have then your imperial blades will be compatible without any modification.

Hi Ratbag
Any chance of a picture or drawing showing how as i am trying to picture this in my head an its hurting my brain trying to understand how it can work
Cheers Rod

Sorry, no pics available, but I'll try to explain in my usual verbose, florid style.

The arbor (output shaft) hangs out the side of your saw. Onto this is fitted firstly a blade flange washer (which may or may not have anti-rotation keyways). This has a hole the same size as the shaft diameter. Onto the flange (or step) on this washer the blade locates. Next goes the pressure washer, which also has a shaft-sized hole. This will be subtly concaved to provide even but firm pressure around its rim onto the blade as the shaft nut is tightened against the blade & double washer assembly. The total assembly is 2 matching washers (one of which is flanged, the other concaved) and tightening nut.

Euro and Oz model saws have a flange washer sized appropriately for locally available blades. Usually 10mm, 20mm or 30mm, and occasionally 25.4mm (1") for older designs like Makita's venerable 9100 saw. To fit a blade bored for a smaller imperial size, one needs to exchange the flanged washer for an appropriately sized imperial equivalent. Apart from fancy-pants tools like Mafell & Festo, all modern USA market tools seem to have blade arbors sized either 5/8" (16mm) or 1" (25.4mm). Order this flange for the equivalent model of saw and your troubles will be over.

Be aware that due to differences of blade arbor size and voltage the exact model designation or number may actually differ for the equivalent models of USA or Oz tools. Just use the specs table and any illustrations to choose the correct USA specific tool from which to order your imperial replacement flange.

Most quality tool manufacturers will supply online exploded parts diagrams for replacement parts ordering. DeWalt seem particularly good in this regard. Just ensure that you search the DeWalt USA site and not the OZ or UK versions, which use metric tooling. The 2 different sized metric & imperial flanged washers will have differing, unique parts numbers as a check that you're not ordering the same metric part you already have.

Order the correct part number from a reputable USA based e-parts supplier and the whole exercise should be fairly rapid, inexpensive and relatively angst free.

Originally Posted by Redbog

Would an engineering shop drilling them out to 30mm, (suitably cooled and clamped), cause problems, does anyone know.

Tool Sharpening, Design & Manufacturing, Tool Repairs & Re-Tipping Services which isn't that far from Wantirna, will be able to resize your the holes on your saw blades and it shouldn't cost you too much. They do this sort of stuff for a living and it'll be spot on.

Any saw doctor will do it, shouldn't cost more than $15. I think that's what we've paid in the past at work